Adhesives, inks and coatings are typically blended formulations consisting of high molecular weight polymers, resins, oils, waxes, pigments, solvents and other additives. In these formulations, it is well known that the resins are major and crucial components needed to impart the formulation rheology and end-use performance characteristics.
Hydrocarbon resins are commonly used in ink formulations containing alkali-refined linseed oil (ARLO). Such resins include, for example, vinyl aromatic-modified dicyclopentadiene (DCPD) resins. These modified DCPD resins are prepared in a two-stage process: polymerization followed by esterification. The two-stage process adds ester functionality to the final resin through a thermal post-esterification.
The vinyl aromatics in modified DCPD resins improve their ARLO compatibility, but typically detract from their end-use performance with other ink vehicle components such as pigments. Additionally, using vinyl aromatics to modify DCPD resins results in darker resins than desired. Thus, there is a need to produce DCPD resins which are compatible with ARLO as well as with the other components of ink and ink vehicle formulations and which have a lighter color.
It is therefore an object of the present invention to provide an improved DCPD resin for ink vehicle formulations and a method of making the resin.
Another object of the present invention is to provide a DCPD resin and method of its production with ARLO compatibility equal or superior to current ink formulation resins without the addition of vinyl aromatics or a time consuming two-stage reaction process.
A further object of the present invention is to provide a DCPD resin with superior compatibility, as compared to current resins, with the various components of ink formulations for a wide range of uses.